Ayer Dpw Water Division, MA
Exceeded the action level in the past
Latest 90th-percentile lead: 1.2 ppb (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
Who runs the water here
Ayer Dpw Water Division serves about 8,479 people through 3,406 service connections, which makes it a medium-sized system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Middlesex County, Massachusetts. EPA system ID: MA2019000; phone on file: 9787728240. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
That is down 1.6 ppb from 2.8 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Ayer Dpw Water Division is 32 ppb across 16 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1.2 ppb |
| 2025 | 2.8 ppb |
| 2024 | 2.7 ppb |
| 2024 | 2.2 ppb |
| 2023 | 7.9 ppb |
| 2023 | 3 ppb |
| 2022 | 4 ppb |
| 2022 | 5 ppb |
| 2021 | 6 ppb |
| 2021 | 32 ppb over 15 |
| 2020 | 6 ppb |
| 2020 | 9 ppb |
| 2019 | 9 ppb |
| 2019 | 5 ppb |
| 2018 | 15 ppb over 10 |
| 2016 | 10 ppb |
Where this result ranks
Of the 535 Massachusetts systems with a lead result, the median latest reading is 1.7 ppb; 13 are over 15 ppb right now and 66 have gone over at some point. Ayer Dpw Water Division's 1.2 ppb sits at the 38th percentile in Massachusetts and the 59th nationally (higher means more lead).
Other water systems in Middlesex County
94 other systems share Middlesex County; 56 of them have a higher latest lead result than Ayer Dpw Water Division. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Lowell Regional Water Utility | 120,418 | 0 (not detected) |
| Cambridge Water Department | 118,214 | 8 ppb |
| Newton Water Dept. (Mwra) | 88,931 | 1.09 ppb |
| Somerville Water Dept. (Mwra) | 81,045 | 6.62 ppb |
| Framingham Water Dept. (Mwra) | 72,362 | 1.74 ppb |
| Malden Water Division (Mwra) | 66,263 | 9.74 ppb |
| Waltham Water Department | 65,218 | 2.24 ppb |
| Medford Water Dept. (Mwra) | 61,700 | 8.31 ppb |
| Everett Water Dept. (Mwra) | 49,075 | 1.25 ppb |
| Arlington Water Dept. (Mwra) | 46,308 | 2.68 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Ayer, MA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Ayer Dpw Water Division whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. Why sampled homes are the worst-case ones is in the guide to reading the number. More in what a past exceedance means today.